Question

A 1.25 kW heater works on a 220 B mains supply. What current rating would a suitable fuse have?

(a) 2 A
(b) 5 A
(c) 10 A
(d) 13 A

Answer 1

(c) 10 A

We know that:
Power, P = V $\times$ I
Current drawn, I = P / V
I = 1250 / 220 (1.25kW = 1250 W)
= 5.68 A
Thus, a suitable fuse would have a current rating of 10 A. If the current exceeds 10 A, the fuse wire will melt.